Ceramic coatings are often applied to jet engine and exhaust components for thermal protection and energy absorption. Ceramic coatings are often formed by applying water-diluted, cement-based ceramic slurries, followed by ambient environment evaporation of the water of solution and elevated temperature curing of the cement to remove water of hydration. The cements are typically silicates of alkali metals and are used to bind together the appropriate ceramic oxides and energy absorbing fillers. The cements may also function as a primer to adhere the coating to a metallic, ceramic or other substrate.
Most ceramic coatings are cured at temperatures of 1,000° Fahrenheit or greater. Ceramic coatings that are applied under normal, ambient conditions and cured at low temperatures tend to crack and fail. Low temperature curable ceramic coatings, with or without a drying control agent, may also crack and fail if applied and cured rapidly.